Stabilization of hydrogen silsequioxane resin solutions

ABSTRACT

A stabilized solution of hydrogen silsesquioxane resin is disclosed. The solution comprises 100 parts by weight solvent, 0.1 to 100 parts by weight hydrogen silsesquioxane resin, and 0.002 to 4 parts by weight acid. These solutions are useful for forming coatings on substrates.

This application is a continuation of application Ser. No. 08/034,435 filed Mar. 19, 1993 which application is now: abandoned

BACKGROUND OF THE INVENTION

The present invention relates to solutions of hydrogen silsesquioxane resin which are stable when stored for extended periods of time. These stable solutions are obtained by incorporating small amounts of acids in the solution.

Hydrogen silsesquioxane resin is known in the art to be useful as a precursor to silica-containing ceramic coatings. For instance, U.S. Pat. No. 4,756,977 granted to Haluska et al. describes a process for forming such a coating in which hydrogen silsesquioxane is diluted in a solvent, applied to a substrate and ceramified by heating.

Various methods for producing hydrogen silsesquioxane resin are also known in the art. For example, U.S. Pat. No. 3,615,272 describes a process for preparing this material which comprises adding trichlorosilane to a reaction medium comprising sulfuric acid and an aromatic hydrocarbon, washing the reaction mixture until neutral and recovering the condensed resin. Despite the fact that the reference teaches hydrolysis and condensation in an acid, the resultant product is neutralized to prevent gelation.

U.S. Pat. No. 5,010,159 teaches a similar process in which a hydridosilane is reacted in an arylsulfonic acid hydrolysis medium followed by separating the resultant resin and then contacting it with a neutralizing agent. Again, however, the resultant resin is neutralized to prevent gelation.

The shelf life of the above hydrogen silsesquioxane resin diluted in a solvent may, however, be variable due to the resin crosslinking and, thus, increasing in molecular weight. The present inventors have now discovered that the incorporation of an acid in the hydrogen silsesquioxane resin solution limits the changes in the molecular weight of the resin.

SUMMARY OF THE INVENTION

The present invention relates to a stabilized solution of hydrogen silsesquioxane resin. The solution comprises 100 parts by weight solvent, 0.1 to 100 parts by weight hydrogen silsesquioxane resin, and 0.002 to 4 parts by weight acid.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is based on the discovery that solutions of hydrogen silsesquioxane can be stabilized by the addition of small amounts of acids. This was particularly unexpected since the prior art teaches neutralization of such solutions to prevent gelation.

As used in the present disclosure, the expressions "stable" or "stabilized" resin solutions are used to describe those solutions in which the molecular weight of the resin changes less over time than those which have not been stabilized. It is preferred that the "stable" solutions not gel. It is more preferred that the Mw of the "stable" solutions not change more than about 100%. It is most preferred that the Mw of the "stable" solutions not change more than about 25%.

The hydrogen silsesquioxane resins (H-resin) which may be used in this invention include hydridosiloxane resins of the formula HSi(OH)_(x) (OR)_(y) O_(z/2), in which each R is independently an organic group or a substituted organic group which, when bonded to silicon through the oxygen atom, forms a hydrolyzable substituent, x=0-2, y=0-2, z=1-3, x+y+z=3. Examples of R include alkyls such as methyl, ethyl, propyl, butyl, etc., aryls such as phenyl, and alkenyls such as allyl or vinyl. As such, these resins may be fully condensed (HSiO_(3/2))_(n) or they may be only partially hydrolyzed (i.e., containing some Si-OR) and/or partially condensed (i.e., containing some Si-OH). Although not represented by this structure, these resins may also contain a small number (eg, less than about 10%) of silicon atoms which have either 0 or 2 hydrogen atoms attached thereto due to various factors involved in their formation or handling.

The above H-resins and methods for their production are known in the art. For example, Collins et al. in U.S. Pat. No. 3,615,272, which is incorporated herein by reference, teach the production of a nearly fully condensed H-resin (which may contain up to 100-300 ppm silanol) by a process comprising hydrolyzing trichlorosilane in a benzenesulfonic acid hydrate hydrolysis medium and then washing the resultant resin with water and/or aqueous sulfuric acid. Similarly, Bank et al. in U.S. Pat. No. 5,010,159, which is hereby incorporated by reference, teach an alternative method comprising hydrolyzing hydridosilanes in an arylsulfonic acid hydrate hydrolysis medium to form a resin which is separated, washed and contacted with a neutralizing agent.

Other hydridosiloxane resins, such as those described by Frye et al. in U.S. Pat. No. 4,999,397, hereby incorporated by reference, those produced by hydrolyzing an alkoxy or acyloxy silane in an acidic, alcoholic hydrolysis medium, those described in Kokai Patent Nos. 59-178749, 60-86017 and 63-107122, or any other equivalent hydridosiloxane, will also function herein.

It is to be noted that in a preferred embodiment of the invention, specific molecular weight fractions of the above H-resins may also be used in this process. Such fraction and methods for their preparation are taught, for example, by Hanneman et al. in U.S. Pat. No. 5,063,267 which is hereby incorporated by reference. Alternative approaches, however, are also contemplated. For example, fractions can also be obtained by a non-solvent precipitation process wherein the hydrogen silsesquioxane is dissolved in a non-polar solvent such as toluene followed by adding a polar solvent such as acetonitrile thereto to precipitate a fraction of the resin. Since this precipitation process progressively precipitates lower molecular weight fractions with higher concentrations of the polar solvent, the process often involves first precipitating and removing the undesired higher molecular weight fractions from the solution followed by precipitating and collecting the desired fraction and leaving the undesired low molecular weight fractions in solution. A preferred fraction comprises material wherein at least 75% of the polymeric species have a molecular weight above about 1200 and a more preferred fraction comprises material wherein at least 75% of the polymeric species have a molecular weight between about 1200 and about 50,000 (relative to polydimethylsiloxane standards).

According to the present invention, the H-resin is merely dissolved in a solvent to form a solution. Various facilitating measures such as stirring and/or heating may be used as necessary. Solvents which may be used include any agent or mixture of agents which will dissolve the H-resin to form a homogenous liquid mixture. These solvents can include, for example, alcohols such as ethyl or isopropyl, aromatic hydrocarbons such as benzene or toluene, alkanes such as n-heptane or dodecane, ketones such as methylisobutylketone, esters, glycol ethers, or cyclic dimethylpolysiloxanes. Particularly preferred herein is methylisobutylketone.

The above solvents are used in an amount sufficient to dissolve the H-resin to the concentration desired for application. Generally, enough of the above solvent is used to form a 0.1-50 wt. percent solids solution (i.e., 100 parts by weight solvent and 0.1 to 100 parts by weight H-resin).

As noted above, these H-resin solutions may be unstable and undergo molecular weight shifts which may not be desirable (eg., the material may deposit a thicker coating, the material may gel, etc.). This instability is dependent on factors such as water, impurities, atmospheric humidity, fractionation and temperature. For example, fractionated material is stable for about 3-4 months under refrigeration (eg., 0° C.) whereas it is only stable for about 1-5 months at room temperature.

According to the present invention, it has been discovered that the addition of a small amount of acid to these solutions can dramatically affect their stability. Although not wishing to be bound by theory, Applicants postulate that both the acidity and the chemical reactions (eg., oxidation, chemical complexing, etc.) of the acids contribute to their effects.

The acids which can be used herein are any which have the desired stabilizing effect without adversely affecting the resin. These can include, for example, inorganic acids such as boric, carbonic, hydrochloric, iodic, nitric, nitrous, phosphoric, phosphorous, sulfuric and sulfurous as well as organic acids such as acetic, benzoic, butyric, citric, formic, lactic, maleic, naphthoic, oxalic, phthalic, picric, propionic, succinic, tartaric, toluic, toluene sulfonic and trifluoroacetic. Of these, nitric acid is particularly preferred.

The above acids are added to the solution in an amount effective to stabilize the H-resin. This amount can vary over a wide range depending on the acid. Generally, however, the acids are added in an amount of between about 0.002 and about 4 parts per weight, and, preferably, between about 0.01 and 0.1 parts per weight, based on the total weight of solution.

It should be noted that the order of mixing the acid, solvent and resin is not critical. For example, in addition to the order described above. the H-resin may be simply dissolved in a solvent-acid mixture.

In addition to the above ingredients, the solution of the present invention may also contain other ingredients. These include, for example, ceramic oxide precursors. Examples of such ceramic oxide precursors include compounds of various metals such as aluminum, titanium, zirconium, tantalum, niobium and/or vanadium as well as various non-metallic compounds such as those of boron or phosphorous which may be dissolved in solution, hydrolyzed, and subsequently pyrolyzed, at relatively low temperatures and relatively rapid reaction rates to form ceramic oxide coatings.

The above ceramic oxide precursor compounds generally have one or more hydrolyzable groups bonded to the above metal or non-metal, depending on the valence of the metal. The number of hydrolyzable groups to be included in these compounds is not critical as long as the compound is soluble in the solvent. Likewise, selection of the exact hydrolyzable substituent is not critical since the substituents are either hydrolyzed or pyrolyzed out of the system. Typical hydrolyzable groups include, but are not limited to, alkoxy, such as methoxy, propoxy, butoxy and hexoxy, acyloxy, such as acetoxy, or other organic groups bonded to said metal or non-metal through an oxygen such as acetylacetonate. Specific compounds, therefore, include zirconium tetracetylacetonate, titanium dibutoxy diacetylacetonate, aluminum triacetylacetonate and tetraisobutoxy titanium

When the hydrogen silsesquioxane resin solution is to be combined with one of the above ceramic oxide precursors, generally it is used in an amount such that the final ceramic coating contains 0.1 to about 30 percent by weight modifying ceramic oxide.

The solution may also contain a platinum, rhodium or copper catalyst to increase the rate and extent of conversion to silica. Generally, any platinum, rhodium or copper compound or complex which can be solubilized will be functional. For instance, a composition such as platinum acetylacetonate, rhodium catalyst RhCl₃ [S(CH₂ CH₂ CH₂ CH₃)₂ ]₃, obtained from Dow Corning Corporation, Midland, Mich., or cupric naphthenate are all within the scope of this invention. These catalysts are,generally added in an amount of between about 5 to 1000 ppm, preferably 5 to 500 ppm platinum, rhodium or copper based on the weight of hydrogen silsesquioxane resin.

The resultant stabilized solutions are useful for forming coatings on various substrates, especially electronic devices.

The following non-limiting Example is provided so that those skilled in the art will more readily understand the invention.

EXAMPLE

Hydrogen silsesquioxane resin was made by the process described in U.S. Pat. No. 3,615,272. Generally, the process comprised slowly adding trichlorosilane to an agitated toluene sulfonic acid hydrate hydrolysis medium. After hydrolysis was complete, the hydrolysis medium was settled and the organic layer (containing the resin) separated and removed. The organic layer was washed twice with sulfuric acid and twice with water and then filtered and stripped to about 20 wt. % solids in toluene.

The H-resin solution was then fractionated by adding acetonitrile to the solution to precipitate out the undesired high molecular weight fractions. The desired molecular weight fraction was then precipitated out of the solution by adding additional acetonitrile.

Two samples were prepared in the above manner and their properties are listed in Table 1 at time 0 (Samples A and B).

The resultant resins were then treated with the acids and their concentrations listed in Table 1 (with a control). Gel permeation chromatography (polydimethylsiloxane standard) was run on the resins at the times listed in the Table (elapsed time) and the results recorded.

As is evident from the data, the addition of an acid to the resin solution clearly inhibits the molecular weight shifts indicative of instability.

                                      TABLE 1                                      __________________________________________________________________________     Acid Stabilization of Hydrogensilsesquioxane Solutions in Methyl Isobutyl      Ketone @ 25 C.                                                                 RESIN                                                                              ACID  ACID   PERCENT                                                                              ELAPSED                                                 LOT #                                                                              TYPE  CONC (ppm)                                                                            SOLIDS (%)                                                                           TIME (days)                                                                           Mn   Mw  Mw/Mn                                                                              Low Mw                                                                              High Mw                        __________________________________________________________________________     A   NONE  0      SOLID 0      6416.8                                                                             12226.9                                                                             1.905                                                                              307  74846                                               20.00                                                                                      7376.7                                                                          23189.0                                                                             3.144                                                                              299  323443                                              20.00                                                                                      6671.4                                                                          44860.2                                                                             6.724                                                                              175  705585                                              20.00                                                                                      8960.6                                                                          72313.6                                                                             8.070                                                                              222  1235785                                             20.00                                                                                      9033.1                                                                          97690.2                                                                             10.815                                                                             258  1504915                                             20.00                                                                                      9033.1                                                                          107622.6                                                                            11.914                                                                             258  1450911                                             20.00                                                                                      8751.3                                                                          155841.7                                                                            17.808                                                                             256  1994484                                         20.00 110    NOT FILTERABLE                                                        20.00                                                                                   123                                                                               9659.0                                                                          187569.9                                                                            19.419                                                                             325  2268874                                             20.00                                                                                   131                                                                               8969.7                                                                          181505.6                                                                            20.236                                                                             316  1885182                                             20.00                                                                                   144                                                                               5964.2                                                                          170787.0                                                                            28.636                                                                             188  1994484                        A      HNO3                                                                                211      SOLID                                                                                      6416.8                                                                          12226.9                                                                             1.905                                                                              307  74846                                               20.00                                                                                      5613.8                                                                          13086.1                                                                             1.979                                                                              307  86436                                               20.00                                                                                      5645.8                                                                          12784.3                                                                             2.264                                                                              179  94193                                               20.00                                                                                      6045.8                                                                          11433.0                                                                             1.891                                                                              201  92251                                               20.00                                                                                      6020.7                                                                          12930.6                                                                             2.148                                                                              256  99051                                               20.00                                                                                      6338.6                                                                          13113.6                                                                             2.069                                                                              256  92251                                               20.00                                                                                      5913.0                                                                          14056.8                                                                             2.377                                                                              256  108793                                              20.00                                                                                   110                                                                               5523.0                                                                          14689.7                                                                             2.660                                                                              252  143114                                              20.00                                                                                   123                                                                               6522.0                                                                          15736.8                                                                             2.413                                                                              225  138192                                              20.00                                                                                   131                                                                               5473.7                                                                          15617.3                                                                             2.853                                                                              316  133275                                              20.00                                                                                   144                                                                               4672.6                                                                          16518.8                                                                             3.535                                                                              196  157917                         A      HNO3                                                                                921      SOLID                                                                                      6416.8                                                                          12226.9                                                                             1.905                                                                              307  74845                                               20.00                                                                                      6672.3                                                                          13095.3                                                                             1.963                                                                              312  94193                                               20.00                                                                                      5661.0                                                                          12574.1                                                                             2.221                                                                              179  94193                                               20.00                                                                                      6159.0                                                                          12026.0                                                                             1.953                                                                              205  94193                                               20.00                                                                                      5826.0                                                                          12318.2                                                                             2.114                                                                              256  86436                                               20.00                                                                                      5511.4                                                                          12163.0                                                                             2.207                                                                              256  94241                                               20.00                                                                                      5885.2                                                                          12482.7                                                                             2.121                                                                              256  85468                                               20.00                                                                                   110                                                                               4872.6                                                                          12327.4                                                                             2.530                                                                              252  94193                                               20.00                                                                                   123                                                                               5540.9                                                                          12610.6                                                                             2.276                                                                              225  103918                                              20.00                                                                                   131                                                                               5021.9                                                                          12245.2                                                                             2.438                                                                              316  84501                                               20.00                                                                                   144                                                                               4000.7                                                                          12316.2                                                                             3.079                                                                              196  94193                          A      BENZOIC                                                                           231       SOLID                                                                                       6416.8                                                                          12226.9                                                                             1.905                                                                              307  74846                                               20.00                                                                                      7323.5                                                                          23942.1                                                                             3.269                                                                              307  303165                                              20.00                                                                                      6344.0                                                                          44083.3                                                                             6.949                                                                              175  632454                                              20.00                                                                                      8705.2                                                                          63564.3                                                                             7.302                                                                              209  1128804                                             20.00                                                                                      9141.9                                                                          81204.2                                                                             8.883                                                                              256  1450911                                             20.00                                                                                      7387.3                                                                          89158.1                                                                             12.069                                                                             256  1396992                                             20.00                                                                                      8638.2                                                                          129935.8                                                                            15.042                                                                             256  1667428                                             20.00                                                                                   110                                                                               8710.6                                                                          153372.2                                                                            17.608                                                                             248  1830634                                             20.00                                                                                   123                                                                               10122.2                                                                         175250.2                                                                            17.313                                                                             325  2434234                                             20.00                                                                                   131                                                                               8808.4                                                                          163357.7                                                                            18.546                                                                             320  1885182                                             20.00                                                                                   144                                                                               6410.5                                                                          185282.5                                                                            28.903                                                                             196  2104051                        A      BENZOIC                                                                           952       SOLID                                                                                       6416.8                                                                          12226.9                                                                             1.905                                                                              307  74846                                               20.00                                                                                      7484.9                                                                          30814.3                                                                             4.117                                                                              295  394788                                              20.00                                                                                      7494.0                                                                          109574.0                                                                            14.622                                                                             175  1667428                                             20.00                                                                                      10367.7                                                                         170529.0                                                                            16.448                                                                             188  2104051                                             20.00                                                                                      9713.4                                                                          211496.9                                                                            21.774                                                                             252  2434234                                         20.00 73     NOT FILTERABLE                                                    20.00 83     SOLUTION GELLED                                  A      H3PO4                                                                              187       SOLID                                                                                      6416.8                                                                          12226.9                                                                             1.905                                                                              307  74846                                           20.00 7      SOLUTION GELLED                                  A      H3PO4                                                                             1110       SOLID                                                                                      6416.8                                                                          12226.9                                                                             1.905                                                                              307  74846                                           20.00 4      SOLUTION GELLED                                  A      F3CCOOH                                                                           192       SOLID                                                                                       6416.8                                                                          12226.9                                                                             1.905                                                                              307  74846                                               20.00                                                                                      6981.0                                                                          14066.0                                                                             2.015                                                                              312  123462                                              20.00                                                                                      6270.4                                                                          16629.2                                                                             2.652                                                                              196  152977                                              20.00                                                                                      7191.9                                                                          20026.5                                                                             2.785                                                                              222  192645                                              20.00                                                                                      6339.5                                                                          15387.5                                                                             2.427                                                                              260  143114                                              20.00                                                                                      6795.5                                                                          32924.7                                                                             4.845                                                                              256  384563                                              20.00                                                                                      7606.8                                                                          56495.3                                                                             7.427                                                                              256  916157                                              20.00                                                                                   110                                                                               8063.8                                                                          81030.3                                                                             10.049                                                                             248  1236785                                             20.00                                                                                   123                                                                               9214.4                                                                          103236.6                                                                            11.204                                                                             329  1450911                                             20.00                                                                                   131                                                                               9713.4                                                                          121992.2                                                                            12.559                                                                             316  1559006                                             20.00                                                                                   144                                                                               7185.6                                                                          147451.0                                                                            20.520                                                                             196  1885182                        A      F3CCOOH                                                                           952       SOLID                                                                                       6416.8                                                                          12226.9                                                                             1.905                                                                              307  74846                                               20.00                                                                                      6413.2                                                                          13342.4                                                                             2.080                                                                              312  123462                                              20.00                                                                                      5353.8                                                                          13369.8                                                                             2.497                                                                              184  123462                                              20.00                                                                                      6297.3                                                                          13809.4                                                                             2.193                                                                              195  118565                                              20.00                                                                                      7423.6                                                                          27213.2                                                                             3.666                                                                              260  313298                                              20.00                                                                                      6827.9                                                                          16564.8                                                                             2.426                                                                              256  143114                                              20.00                                                                                      7667.2                                                                          21304.8                                                                             2.779                                                                              256  190654                                              20.00                                                                                   110                                                                               6259.6                                                                          25208.1                                                                             4.027                                                                              252  272844                                              20.00                                                                                   123                                                                               7524.6                                                                          30964.2                                                                             4.115                                                                              316  405023                                              20.00                                                                                   131                                                                               6833.4                                                                          34145.9                                                                             4.997                                                                              316  405023                                              20.00                                                                                   144                                                                               5846.6                                                                          43496.1                                                                             7.440                                                                              196  632454                         A      H3BO3                                                                              269       SOLID                                                                                      6416.8                                                                          12226.9                                                                             1.905                                                                              307  74848                                               20.00                                                                                      6599.4                                                                          13342.4                                                                             2.022                                                                              299  99051                                               20.00                                                                                      5739.0                                                                          13882.7                                                                             2.419                                                                              179  103918                                              20.00                                                                                      6442.9                                                                          14341.0                                                                             2.226                                                                              188  143114                                              20.00                                                                                      6817.1                                                                          15360.0                                                                             2.263                                                                              260  148043                                              20.00                                                                                      6218.2                                                                          15911.5                                                                             2.559                                                                              256  148043                                              20.00                                                                                      6124.8                                                                          18039.6                                                                             2.945                                                                              256  172770                                              20.00                                                                                   110                                                                               6626.4                                                                          19573.2                                                                             2.954                                                                              252  192645                                              20.00                                                                                   123                                                                               6953.1                                                                          21341.9                                                                             3.069                                                                              325  222598                                              20.00                                                                                   131                                                                               6558.9                                                                          22288.1                                                                             3.398                                                                              316  212596                                              20.00                                                                                   144                                                                               5124.7                                                                          23728.2                                                                             4.630                                                                              179  217595                         A      H3BO3                                                                              914       SOLID                                                                                      6416.8                                                                          12226.9                                                                             1.905                                                                              307  74846                                               20.00                                                                                      6752.3                                                                          13150.2                                                                             1.947                                                                              307  94193                                               20.00                                                                                      6125.7                                                                          13177.6                                                                             2.151                                                                              201  94678                                               20.00                                                                                      4752.9                                                                          11797.9                                                                             2.482                                                                              188  99051                                               20.00                                                                                      6362.9                                                                          13846.1                                                                             2.176                                                                              256  133275                                              20.00                                                                                      6217.3                                                                          14194.3                                                                             2.283                                                                              256  133275                                              20.00                                                                                      5523.9                                                                          15148.7                                                                             2.742                                                                              256  143114                                              20.00                                                                                   110                                                                               5587.5                                                                          16187.4                                                                             2.897                                                                              252  164843                                              20.00                                                                                   123                                                                               6255.7                                                                          17163.5                                                                             2.700                                                                              325  167814                                              20.00                                                                                   131                                                                               6163.5                                                                          18233.4                                                                             2.958                                                                              316  157917                                              20.00                                                                                   144                                                                               4733.3                                                                          19471.4                                                                             4.114                                                                              196  172770                         A      p-TSA                                                                              183       SOLID                                                                                      6416.8                                                                          12226.9                                                                             1.905                                                                              307  74846                                               20.00                                                                                      6682.1                                                                          12866.6                                                                             1.926                                                                              307  92251                                               20.00                                                                                      5594.7                                                                          12336.5                                                                             2.205                                                                              184  85468                                               20.00                                                                                      5528.4                                                                          11387.5                                                                             2.060                                                                              188  93222                                               20.00                                                                                      5337.6                                                                          12035.2                                                                             2.255                                                                              256  94678                                               20.00                                                                                      4844.9                                                                          11907.4                                                                             2.458                                                                              256  94241                                               20.00                                                                                      4560.2                                                                          11843.5                                                                             2.597                                                                              256  93222                                               20.00                                                                                   110                                                                               4461.2                                                                          11807.0                                                                             2.647                                                                              252  94193                                               20.00                                                                                   123                                                                               4761.9                                                                          11807.0                                                                             2.479                                                                              325  89342                                               20.00                                                                                   131                                                                               3880.6                                                                          12190.4                                                                             3.141                                                                              188  94193                                               20.00                                                                                   144                                                                               3826.4                                                                          12446.1                                                                             3.253                                                                              196  94678                          A      p-TSA                                                                              990       SOLID                                                                                      6416.8                                                                          12226.9                                                                             1.905                                                                              307  74846                                               20.00                                                                                      6428.5                                                                          12756.9                                                                             1.984                                                                              307  94193                                               20.00                                                                                      4493.3                                                                          12035.2                                                                             2.678                                                                              201  94193                                               20.00                                                                                      4521.8                                                                          11423.9                                                                             2.526                                                                              201  84501                                               20.00                                                                                      4992.4                                                                          12638.0                                                                             2.531                                                                              256  94678                                               20.00                                                                                      4636.0                                                                          13067.8                                                                             2.819                                                                              256  133275                                              20.00                                                                                      4489.7                                                                          14680.5                                                                             3.270                                                                              256  138192                                              20.00                                                                                   110                                                                               4275.8                                                                          15102.8                                                                             3.532                                                                              248  157917                                              20.00                                                                                   123                                                                               4561.9                                                                          16242.7                                                                             3.560                                                                              320  172770                                              20.00                                                                                   131                                                                               4388.9                                                                          19785.9                                                                             4.508                                                                              188  192645                                              20.00                                                                                   144                                                                               4009.6                                                                          21518.0                                                                             5.367                                                                              196  282937                         A      ACETIC                                                                            192        SOLID                                                                                      6416.8                                                                          12226.9                                                                             1.905                                                                              307  74846                                               20.00                                                                                      7468.7                                                                          24779.7                                                                             3.318                                                                              312  293044                                              20.00                                                                                      6617.4                                                                          52261.6                                                                             7.898                                                                              192  863313                                              20.00                                                                                      9033.1                                                                          77690.2                                                                             8.601                                                                              222  1289426                                             20.00                                                                                      9314.1                                                                          103139.2                                                                            11.073                                                                             256  1559006                                             20.00                                                                                      9804.2                                                                          130034.0                                                                            13.263                                                                             256  1559006                                             20.00                                                                                   110                                                                               9087.5                                                                          180114.8                                                                            19.820                                                                             248  2104051                                             20.00                                                                                   123                                                                               10440.4                                                                         194836.5                                                                            18.662                                                                             329  2213872                                             20.00                                                                                   131                                                                               8869.1                                                                          174456.5                                                                            19.670                                                                             320  1939799                                             20.00                                                                                   144                                                                               6448.3                                                                          183393.7                                                                            28.441                                                                             184  1776158                        A      ACETIC                                                                            1019      SOLID                                                                                       6416.8                                                                          12226.9                                                                             1.905                                                                              307  74846                                               20.00                                                                                      7758.4                                                                          31685.1                                                                             4.084                                                                              299  394788                                              20.00                                                                                      7387.5                                                                          104015.9                                                                            14.080                                                                             171  1450911                                             20.00                                                                                      9786.1                                                                          172076.0                                                                            17.584                                                                             184  1939799                                             20.00                                                                                      9740.7                                                                          211097.3                                                                            21.672                                                                             260  2379056                                             20.00                                                                                      7280.2                                                                          180710.8                                                                            24.822                                                                             256  1994484                                         20.00 94     SOLUTION GELLED                                  B      NONE                                                                                  0      SOLID                                                                                      4120.8                                                                          10804.4                                                                             2.622                                                                              282  67152                                               20.00                                                                                      4094.1                                                                          11269.0                                                                             2.752                                                                              282  75810                                               20.00                                                                                      4348.8                                                                          11715.8                                                                             2.694                                                                              269  80634                                               20.00                                                                                      4178.7                                                                          12007.8                                                                             2.874                                                                              265  84501                                               20.00                                                                                      3892.2                                                                          12236.0                                                                             3.144                                                                              256  99051                                               20.00                                                                                      3881.5                                                                          12857.5                                                                             3.312                                                                              256  94193                                               20.00                                                                                      4619.0                                                                          14331.9                                                                             3.103                                                                              256  108793                                              20.00                                                                                   105                                                                               4569.1                                                                          15332.4                                                                             3.356                                                                              256  143114                                              20.00                                                                                   119                                                                               4955.7                                                                          16343.9                                                                             3.296                                                                              325  157917                                              20.00                                                                                   127                                                                               4501.3                                                                          16666.1                                                                             3.703                                                                              258  152977                                              20.00                                                                                   140                                                                               4076.3                                                                          16933.2                                                                             4.154                                                                              248  152977                         B      HNO3                                                                                170      SOLID                                                                                      4120.8                                                                          10804.4                                                                             2.622                                                                              282  67152                                               20.00                                                                                      4218.8                                                                          11341.9                                                                             2.588                                                                              286  71958                                               20.00                                                                                      4127.1                                                                          11241.6                                                                             2.724                                                                              256  81117                                               20.00                                                                                      4062.1                                                                          11223.4                                                                             2.763                                                                              265  79669                                               20.00                                                                                      4006.9                                                                          11414.8                                                                             2.849                                                                              265  81600                                               20.00                                                                                      3589.3                                                                          11907.4                                                                             3.317                                                                              258  84501                                               20.00                                                                                      4479.0                                                                          12628.9                                                                             2.820                                                                              258  94193                                               20.00                                                                                   105                                                                               4477.2                                                                          13040.4                                                                             2.913                                                                              266  94678                                               20.00                                                                                   119                                                                               4571.8                                                                          13992.7                                                                             3.061                                                                              329  128365                                              20.00                                                                                   127                                                                               4347.1                                                                          13937.7                                                                             3.206                                                                              265  113676                                              20.00                                                                                   140                                                                               4120.8                                                                          13928.5                                                                             3.380                                                                              299  128365                         B      HNO3                                                                                458      SOLID                                                                                      4120.8                                                                          10804.4                                                                             2.622                                                                              282  67152                                               20.00                                                                                      4255.3                                                                          11323.7                                                                             2.661                                                                              299  75810                                               20.00                                                                                      4206.3                                                                          11223.4                                                                             2.668                                                                              269  75810                                               20.00                                                                                      4186.7                                                                          11250.7                                                                             2.687                                                                              273  77738                                               20.00                                                                                      4033.6                                                                          10913.7                                                                             2.706                                                                              265  75810                                               20.00                                                                                      3745.6                                                                          11305.4                                                                             3.018                                                                              256  76774                                               20.00                                                                                      4315.9                                                                          11341.9                                                                             2.628                                                                              260  75810                                               20.00                                                                                   105                                                                               4305.2                                                                          11232.5                                                                             2.609                                                                              258  79669                                               20.00                                                                                   119                                                                               4517.3                                                                          11524.2                                                                             2.551                                                                              329  94193                                               20.00                                                                                   127                                                                               4039.8                                                                          11469.5                                                                             2.839                                                                              260  81600                                               20.00                                                                                   140                                                                               3841.5                                                                          11086.7                                                                             2.886                                                                              273  74846                          B      BENZOIC                                                                           100       SOLID                                                                                       4120.8                                                                          10804.4                                                                             2.622                                                                              282  67152                                               20.00                                                                                      4096.8                                                                          11177.8                                                                             2.728                                                                              286  78703                                               20.00                                                                                      4493.3                                                                          11962.1                                                                             2.662                                                                              265  80634                                               20.00                                                                                      4148.4                                                                          12117.3                                                                             2.921                                                                              256  86436                                               20.00                                                                                      4226.8                                                                          12683.8                                                                             3.001                                                                              269  99051                                               20.00                                                                                      4054.1                                                                          13232.5                                                                             3.264                                                                              258  99051                                               20.00                                                                                      4666.3                                                                          14781.4                                                                             3.168                                                                              258  123462                                              20.00                                                                                   105                                                                               4663.7                                                                          15433.5                                                                             3.309                                                                              258  143114                                              20.00                                                                                   119                                                                               4995.9                                                                          16822.6                                                                             3.367                                                                              325  157917                                              20.00                                                                                   127                                                                               4763.6                                                                          17615.2                                                                             3.698                                                                              273  162863                                              20.00                                                                                   140                                                                               4661.9                                                                          18214.9                                                                             3.907                                                                              269  162863                         B      BENZOIC                                                                           490       SOLID                                                                                       4120.8                                                                          10804.4                                                                             2.622                                                                              282  67152                                               20.00                                                                                      4251.7                                                                          11378.3                                                                             2.676                                                                              290  75810                                               20.00                                                                                      3964.2                                                                          11825.2                                                                             2.983                                                                              273  89342                                               20.00                                                                                      3971.3                                                                          11524.2                                                                             2.902                                                                              265  77738                                               20.00                                                                                      4191.2                                                                          12766.0                                                                             3.046                                                                              256  99051                                               20.00                                                                                      4432.6                                                                          13552.9                                                                             3.058                                                                              256  94241                                               20.00                                                                                      4621.7                                                                          14653.0                                                                             3.170                                                                              256  138192                                              20.00                                                                                   105                                                                               4683.3                                                                          15516.2                                                                             3.313                                                                              256  143114                                              20.00                                                                                   119                                                                               5122.0                                                                          16702.9                                                                             3.261                                                                              325  140160                                              20.00                                                                                   127                                                                               4586.9                                                                          17200.4                                                                             3.750                                                                              269  148043                                              20.00                                                                                   140                                                                               4446.9                                                                          17827.4                                                                             4.009                                                                              273  157917                         B      H3PO4                                                                              170       SOLID                                                                                      4120.8                                                                          10804.4                                                                             2.622                                                                              282  67152                                               20.00                                                                                      5555.3                                                                          16868.7                                                                             3.037                                                                              290  2104051                                         20.00 13     SOLUTION GELLED                                  B      H3PO4                                                                              560       SOLID                                                                                      4120.8                                                                          10804.4                                                                             2.622                                                                              282  67162                                               20.00                                                                                      4283.8                                                                          11360.1                                                                             2.652                                                                              290  74846                                               20.00                                                                                      4145.8                                                                          11159.6                                                                             2.692                                                                              273  79669                                               20.00                                                                                      4150.2                                                                          11341.9                                                                             2.733                                                                              269  80634                                               20.00                                                                                      4001.6                                                                          11450.4                                                                             2.864                                                                              273  92251                                               20.00                                                                                      3822.0                                                                          11925.6                                                                             3.120                                                                              256  89342                                               20.00                                                                                      4499.5                                                                          12409.6                                                                             2.758                                                                              260  93222                                               20.00                                                                                   105                                                                               4408.5                                                                          13012.9                                                                             2.952                                                                              256  94193                                               20.00                                                                                   119                                                                               4694.0                                                                          13800.2                                                                             2.940                                                                              329  113676                                              20.00                                                                                   127                                                                               4411.2                                                                          14148.5                                                                             3.207                                                                              265  118565                                              20.00                                                                                   140                                                                               4339.0                                                                          15176.2                                                                             3.498                                                                              269  143114                         B      F3CCOOH                                                                           138       SOLID                                                                                       4120.8                                                                          10804.4                                                                             2.622                                                                              282  67152                                               20.00                                                                                      4342.6                                                                          11542.5                                                                             2.658                                                                              299  76774                                               20.00                                                                                      4195.6                                                                          11734.0                                                                             2.797                                                                              269  81600                                               20.00                                                                                      4158.2                                                                          12117.3                                                                             2.914                                                                              265  89342                                               20.00                                                                                      4128.2                                                                          12656.3                                                                             3.066                                                                              260  99051                                               20.00                                                                                      4223.2                                                                          13580.4                                                                             3.216                                                                              256  94678                                               20.00                                                                                      4951.2                                                                          15213.0                                                                             3.073                                                                              273  143114                                              20.00                                                                                   105                                                                               4802.9                                                                          15123.0                                                                             3.357                                                                              256  152977                                              20.00                                                                                   119                                                                               5185.5                                                                          17569.1                                                                             3.388                                                                              329  167814                                              20.00                                                                                   127                                                                               4710.1                                                                          17762.8                                                                             3.771                                                                              269  148043                                              20.00                                                                                   140                                                                               4659.2                                                                          18759.7                                                                             4.026                                                                              273  172770                         B      F3CCOOH                                                                           488       SOLID                                                                                       4120.8                                                                          10804.4                                                                             2.622                                                                              282  67152                                               20.00                                                                                      4194.7                                                                          11378.3                                                                             2.713                                                                              290  76774                                               20.00                                                                                      4092.4                                                                          11442.2                                                                             2.796                                                                              265  75810                                               20.00                                                                                      4089.7                                                                          11697.5                                                                             2.860                                                                              265  80634                                               20.00                                                                                      3938.4                                                                          11962.1                                                                             3.037                                                                              260  90312                                               20.00                                                                                      3918.0                                                                          12665.5                                                                             3.233                                                                              258  93222                                               20.00                                                                                      4705.6                                                                          14524.5                                                                             3.087                                                                              258  118565                                              20.00                                                                                   105                                                                               4823.5                                                                          15773.6                                                                             3.270                                                                              256  152977                                              20.00                                                                                   119                                                                               5131.8                                                                          16905.5                                                                             3.294                                                                              329  152977                                              20.00                                                                                   127                                                                               4646.7                                                                          17421.6                                                                             3.749                                                                              290  157917                                              20.00                                                                                   140                                                                               4505.7                                                                          18298.0                                                                             4.061                                                                              265  167814                         B      H3BO3                                                                              110       SOLID                                                                                      4120.8                                                                          10804.4                                                                             2.622                                                                              282  67152                                               20.00                                                                                      4173.4                                                                          11086.7                                                                             2.657                                                                              290  74846                                               20.00                                                                                      4023.8                                                                          11405.7                                                                             2.835                                                                              265  77738                                               20.00                                                                                      4340.8                                                                          11697.5                                                                             2.695                                                                              265  84501                                               20.00                                                                                      4280.2                                                                          12053.4                                                                             2.816                                                                              269  92251                                               20.00                                                                                      3823.8                                                                          12446.1                                                                             3.255                                                                              256  92251                                               20.00                                                                                      4661.9                                                                          13360.7                                                                             2.888                                                                              260  94193                                               20.00                                                                                   105                                                                               4510.2                                                                          13763.6                                                                             3.052                                                                              258  108793                                              20.00                                                                                   119                                                                               4966.4                                                                          14827.3                                                                             2.986                                                                              325  133275                                              20.00                                                                                   127                                                                               4438.9                                                                          14854.9                                                                             3.347                                                                              299  118565                                              20.00                                                                                   140                                                                               4414.8                                                                          15755.2                                                                             3.569                                                                              265  143114                         B      H3BO3                                                                              445       SOLID                                                                                      4120.8                                                                          10804.4                                                                             2.622                                                                              282  67152                                           20.00 6      SOLUTION GELLED                                  B      p-TSA                                                                              180       SOLID                                                                                      4120.8                                                                          10804.4                                                                             2.622                                                                              282  67152                                               20.00                                                                                      4252.6                                                                          11295.3                                                                             2.656                                                                              295  74846                                               20.00                                                                                      4216.1                                                                          10959.2                                                                             2.599                                                                              273  69553                                               20.00                                                                                      3987.4                                                                          10804.4                                                                             2.710                                                                              265  74846                                               20.00                                                                                      3750.9                                                                          10522.3                                                                             2.805                                                                              260  70034                                               20.00                                                                                      3740.2                                                                          11013.9                                                                             2.945                                                                              256  74846                                               20.00                                                                                      4283.8                                                                          10677.3                                                                             2.539                                                                              260  74846                                               20.00                                                                                   105                                                                               4309.6                                                                          10804.4                                                                             2.507                                                                              278  80634                                               20.00                                                                                   119                                                                               4368.4                                                                          10895.5                                                                             2.494                                                                              325  74846                                               20.00                                                                                   127                                                                               3950.9                                                                          11032.1                                                                             2.792                                                                              248  80634                                               20.00                                                                                   140                                                                               3691.4                                                                          10576.9                                                                             2.865                                                                              265  72920                          B      p-TSA                                                                              550       SOLID                                                                                      4120.8                                                                          10804.4                                                                             2.622                                                                              282  67152                                               20.00                                                                                      4192.1                                                                          11187.0                                                                             2.669                                                                              286  74846                                               20.00                                                                                      3926.0                                                                          10904.6                                                                             2.778                                                                              269  84501                                               20.00                                                                                      3740.2                                                                          10631.5                                                                             2.842                                                                              265  74846                                               20.00                                                                                      3437.6                                                                          10304.0                                                                             2.997                                                                              260  72882                                               20.00                                                                                      3454.4                                                                          11004.8                                                                             3.186                                                                              256  84501                                               20.00                                                                                      4208.1                                                                          11241.6                                                                             2.671                                                                              260  78703                                               20.00                                                                                   105                                                                               3966.9                                                                          11004.8                                                                             2.774                                                                              260  77738                                               20.00                                                                                   119                                                                               4139.5                                                                          11542.5                                                                             2.788                                                                              329  94193                                               20.00                                                                                   127                                                                               3958.0                                                                          12391.3                                                                             3.131                                                                              256  94241                                               20.00                                                                                   140                                                                               3705.6                                                                          12281.7                                                                             3.314                                                                              269  92251                          B      ACETIC                                                                            148        SOLID                                                                                      4120.8                                                                          10804.4                                                                             2.622                                                                              282  67152                                               20.00                                                                                      4286.5                                                                          11332.8                                                                             2.644                                                                              286  74846                                               20.00                                                                                      4247.3                                                                          11852.6                                                                             2.791                                                                              265  84501                                               20.00                                                                                      4422.8                                                                          12327.4                                                                             2.787                                                                              265  89342                                               20.00                                                                                      4112.8                                                                          12574.1                                                                             3.057                                                                              260  99051                                               20.00                                                                                      4407.7                                                                          13552.9                                                                             3.075                                                                              256  103918                                              20.00                                                                                      4715.4                                                                          14726.4                                                                             3.123                                                                              260  128365                                              20.00                                                                                   105                                                                               4788.7                                                                          15746.0                                                                             3.288                                                                              256  133275                                              20.00                                                                                   119                                                                               4910.1                                                                          16684.5                                                                             3.398                                                                              325  143114                                              20.00                                                                                   140                                                                               4371.1                                                                          17587.6                                                                             4.024                                                                              252  152977                         B      ACETIC                                                                            577        SOLID                                                                                      4120.8                                                                          10804.4                                                                             2.622                                                                              282  67152                                               20.00                                                                                      4213.4                                                                          11323.7                                                                             2.688                                                                              295  74846                                               20.00                                                                                      4406.8                                                                          12099.1                                                                             2.745                                                                              282  91281                                               20.00                                                                                      4075.4                                                                          12144.7                                                                             2.980                                                                              265  87889                                               20.00                                                                                      4160.0                                                                          12811.7                                                                             3.080                                                                              260  94678                                               20.00                                                                                      3880.6                                                                          13736.1                                                                             3.540                                                                              256  103918                                              20.00                                                                                      4725.3                                                                          15295.7                                                                             3.237                                                                              256  128365                                              20.00                                                                                   105                                                                               4626.2                                                                          16150.6                                                                             3.491                                                                              256  143114                                              20.00                                                                                   119                                                                               5044.2                                                                          17467.7                                                                             3.463                                                                              325  152977                                              20.00                                                                                   127                                                                               4756.5                                                                          18261.1                                                                             3.839                                                                              260  143114                                              20.00                                                                                   140                                                                               4337.3                                                                          18556.5                                                                             4.278                                                                              248  167814                         __________________________________________________________________________ 

That which is claimed is:
 1. A hydrogen silsesquioxane resin solution consisting essentially of:100 parts by weight solvent; 0.1 to 100 parts by weight hydrogen silsesquioxane resin represented by the formula (HSiO_(3/2))_(n) and containing 100 to 300 ppm silanol, wherein n is an even integer of 10 or more; and 0.002 to 4 parts by weight acid.
 2. The solution of claim 1 wherein at least 75% of the polymeric species of the resin have a molecular weight between about 1200 and about 50,000.
 3. The solution of claim 1 wherein the solvent is selected from the group consisting of alcohols, aromatic hydrocarbons, alkanes, ketones, esters, glycol ethers, and cyclic dimethylpolysiloxanes.
 4. The solution of claim 1 wherein the solvent is methylisobutylketone.
 5. The solution of claim 1 wherein the acid is an inorganic acid.
 6. The solution of claim 1 wherein the acid is selected from the group consisting of boric, carbonic, hydrochloric, iodic, nitric, nitrous, phosphoric, phosphorous, sulfuric and sulfurous.
 7. The solution of claim 1 wherein the acid is nitric.
 8. The solution of claim 1 wherein the acid is boric.
 9. The solution of claim 1 wherein the acid is phosphoric.
 10. The solution of claim 1 wherein the acid is phosphorous.
 11. The solution of claim 1 wherein the acid is an organic acid.
 12. The solution of claim 11 wherein the acid is selected from the group consisting of acetic, benzoic, butyric, citric, formic, lactic, maleic, naphthoic, oxalic,, phthalic, picric, propionic, succinic, tartaric, toluic, toluene sulfonic and trifluoroacetic.
 13. The solution of claim 1 wherein the acid is included in an amount between about 0.01 and 0-1 parts by weight.
 14. A hydrogen silsesquioxane resin solution consisting essentially of:100 parts by weight solvent; 0.1 to 100 parts by weight hydrogen silsesquioxane resin represented by the formula (HSiO_(3/2))_(n) and containing 100 to 300 ppm silanol wherein n is an even integer of 10 or more; 0.002 to 4 parts by weight acid: and modifying ceramic oxide precursors comprising a compound containing an element selected from the group consisting of titanium, zirconium, aluminum, tantalum, vanadium, niobium, boron and phosphorous wherein the compound contains at least one hydrolyzable substituent selected from the group consisting of alkoxy or acyloxy and the compound is present in an amount such that the coating contains 0.1 to 30 percent by weight modifying ceramic oxide.
 15. A hydrogen silsesquioxane resin solution consisting essentially of:100 parts by weight solvent; 0.1 to 100 parts by weight hydrogen silsesquioxane resin represented by the formula (HSiO_(3/2))_(n) and containing 100 to 300 ppm silanol wherein n is an even integer of 10 or more; 0.002 to 4 parts by weight acid; and a platinum, rhodium or copper catalyst in an amount of between about 5 and about 500 ppm platinum, rhodium or copper based on the weight of hydrogen silsesquioxane resin. 